Errors at pasting Dupes

Hello Guys,
since yesterday there is something strange happening on my server.
Everytime i try to paste an AdvDupe who contains some re-weight-ed parts i get some lua-errors:


[AdvDupe2Notify]	Pasting...
Error applying entity modifer, "mass". ERROR: [@lua/includes/extensions/table.lua:82] bad argument #1 to 'pairs' (table expected, got Entity)
Error applying entity modifer, "mass". ERROR: [@lua/includes/extensions/table.lua:82] bad argument #1 to 'pairs' (table expected, got Entity)
[AdvDupe2Notify]	Finished Pasting!

The weird Thing is that it works perfect in Singleplayer whit exact the same Addon setup.
The Server is running on a AMD Opteron™ 3280 (8x2,4GHz), 16GB-DDR3 RAM with Debian as OS - just if somebody asks.

Things i allready tried:
Updating the Game Server
Re-Download the entire Garrysmod folder
Switching out AdvDupe whit AdvDupe2
Switching between some Weight-Tool versions
Only running the Server with AdvDupe and Weight-tool - still the same error

I hope somebody can help me.